On average, a person with a bachelor's degree earns a person with a master's degree and than a person with a phd.

Increased earning income from bachelors, masters and doctoral

Explanation:

U.S. Government article , titled "Lifetime Earnings Soar With Education: Master degree for $2.5 million in income for a whole lifespan," we see that advanced masters and professional degree programs make an excellent investment.

PhD makes an astounding $2.2 million more than a graduate of high school.

Doctoral students-$ 1.3 million receive more than a bachelor's degree.

Doctorate Masters-Doctors earn $900,000 more than Masters.

Everyone who has been to college knows that if you cannot succeed at pre-med or engineering, students fall-back into Business Administration or Nursing.  If they fail in Business or nursing they pursue liberal arts or social science  (i.e. Psychology, Economics), and if they fail all else, students graduate with degree in Education or Art History.

answer(c) factors of production;